/*
 * Copyright (C) 2010-2018 Gordon Fraser, Andrea Arcuri and EvoSuite
 * contributors
 *
 * This file is part of EvoSuite.
 *
 * EvoSuite is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3.0 of the License, or
 * (at your option) any later version.
 *
 * EvoSuite is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with EvoSuite. If not, see <http://www.gnu.org/licenses/>.
 */
package org.evosuite.testsuite;

import org.evosuite.Properties;
import org.evosuite.ga.ReplacementFunction;

/**
 * <p>
 * TestSuiteReplacementFunction class.
 * </p>
 *
 * @author Gordon Fraser
 */
public class TestSuiteReplacementFunction extends ReplacementFunction<TestSuiteChromosome> {

    private static final long serialVersionUID = -8472469271120247395L;

    /**
     * <p>
     * Constructor for TestSuiteReplacementFunction.
     * </p>
     *
     * @param maximize a boolean.
     */
    public TestSuiteReplacementFunction(boolean maximize) {
        super(maximize);
    }

    /**
     * <p>
     * Constructor for TestSuiteReplacementFunction.
     * </p>
     */
    public TestSuiteReplacementFunction() {
        super(false);
    }

    /**
     * <p>
     * getLengthSum
     * </p>
     *
     * @param chromosome1 a {@link org.evosuite.testsuite.AbstractTestSuiteChromosome}
     *                    object.
     * @param chromosome2 a {@link org.evosuite.testsuite.AbstractTestSuiteChromosome}
     *                    object.
     * @return a int.
     */
    public int getLengthSum(TestSuiteChromosome chromosome1, TestSuiteChromosome chromosome2) {
        return chromosome1.totalLengthOfTestCases() + chromosome2.totalLengthOfTestCases();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean keepOffspring(TestSuiteChromosome parent1, TestSuiteChromosome parent2,
                                 TestSuiteChromosome offspring1, TestSuiteChromosome offspring2) {

        // -1 if offspring has lower fitness, +1 if parent has lower fitness
        int cmp = compareBestOffspringToBestParent(parent1, parent2, offspring1, offspring2);

        if (Properties.CHECK_PARENTS_LENGTH) {

            int offspringLength = getLengthSum(offspring1, offspring2);
            int parentLength = getLengthSum(parent1, parent2);

            //if equivalent, only accept if it does not increase the length
            if (cmp == 0 && offspringLength <= parentLength) {
                return true;
            } else {
                if (maximize) {
                    return cmp > 0;
                } else {
                    return cmp < 0;
                }
            }
        } else {
            //default check
            if (maximize) {
                return cmp >= 0;
            } else {
                return cmp <= 0;
            }
        }
    }
}
